The present invention relates generally to manufacturing system for electronic products, and more particularly to a micro device feeder system used in a manufacturing system.
Certain operations of electronic circuit board assembly involved supplying micro devices by a micro device feeder to a robotic handling system. The micro devices include a broad range of electronic and mechanical devices, such as programmable devices. Programmable devices, which include but are not limited to devices such as Flash memories (Flash), electrically erasable programmable read only memories (E2PROM), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), and microcontrollers.
The micro device feeders are generally aligned and connected underneath the robotic handling system. The micro devices are typically supplied in tape on reel. The tape includes a plurality of pockets for containing the micro devices. Typically, there is only one pocket across the width of the tape. The tape has sprocket holes or perforations in one side so that it can be driven through the micro device feeder.
The micro device feeder has a frame upon which a motor and pulley arrangement is mounted to drive a sprocket, which engages the perforations to linearly drive the tape through the micro device feeder. The frame also carries a spring-loaded backup plate to support the tape and also accommodate any sudden variations in tension in the tape.
The robotic handling system removes the micro devices as the micro device feeder in the tape linearly presents them and places them on buffer areas of the micro device feeder or directly on printed circuit boards moving through an electronic assembly line or manufacturing system. In high-speed systems, the robotic handling systems are linearly moving pick-and-place mechanisms. In such a system, the centerline of the linearly moving pick-and-place mechanism must coincide with the centerline of the pockets in the linearly moving tape.
A major problem associated with the handling of micro devices carried on tapes is that different micro device feeders are needed for different size micro devices because they must be supplied in different size tapes. For example, three different micro device feeders are required for 16-, 24-, and 32-millimeter wide tape. The reason for requiring a different micro device feeder is that the centerline of the linearly moving pick-and-place mechanism does not coincide with the centerline of the pockets in the linearly moving tape for different tape widths because of the perforations in the side of the tape.
The perforations in the tape cause a different offset between the centerline of the pockets and the centerline of the tape for each different tape width. Since the frame is connected to the robotic handling system and also to the motor and pulley arrangement and the sprocket, the centerline of the linearly moving pick-and-place mechanism is fixed relative to the centerline of the sprocket. The centerline of the sprocket fixes the centerline of the perforations, which means that the offset causes the centerline of the pick-and-place mechanism to not coincide with the centerline of the pockets.
Since there can be a large offset and most companies use different size tape widths, companies require a large number of different size micro device feeders, which is quite inconvenient and expensive.
Different approaches have been taken to try to solve this problem. One approach involves using a tape module, which forms a portion of the micro device feeder. The tape module is replaced for supplying micro devices contained in tapes with different widths. Therefore, instead of replacing the entire micro device feeder to accommodate for different size tape, only the corresponding tape module needs to be replaced. However, the tape module often constitutes almost half of the mechanism of a micro device feeder so it is still inconvenient and expensive to stock large number of tape modules to handle different size tapes.
Thus, those skilled in the art have long sought a micro device feeder, which is easily adjustable to accommodate micro devices supplied on tapes with different widths and is simple and inexpensive. Previous systems by those skilled in the art have been unsuccessful in providing a fully adequate solution.
The present invention provides a micro device feeder system, which is easily adjustable to accommodate micro devices supplied on tapes with different widths. The micro device feeder system is simple and inexpensive.
The present invention further provides a micro device feeder, which is adjustable to accommodate micro devices supplied on tapes with different widths. A mounting plate has a movable drive plate slidably mounted thereto. An input mechanism on the movable drive plate receives micro devices contained in a tape. A sprocket engages and advances the tape under motor drive. A feeder width adjustment mechanism allows for movement of the movable drive plate relative to the mounting plate for adjusting the sprocket to accommodate tapes with different widths where the distance between the tape and sprocket centerlines change. The feeder width adjustment mechanism includes a pin coupled to the mounting plate, a securing device coupled to the movable drive plate and is capable of moving along the pin, and a locking mechanism capable of securing the securing device to the pin to lock the movable drive plate relative to the mounting plate.